The invention relates to brushware, e.g. a brush, paintbrush, etc., which is exposed to moisture during use and which has a bristle carrier and a bristle facing at least partly comprising individual, standing plastic bristles.
Brushware which is exposed to moisture, either through use in a moist atmosphere for cleaning purposes, e.g. toothbrushes, or for the application of wet media, e.g. paintbrushes, only dry incompletely after use because the bristles are combined into bundles, and the moisture is retained for a long time in the narrow capillaries between the bristles. This moist atmosphere forms ideal conditions for the settling or deposition and growth of bacteria and microbes. This disadvantageous effect is assisted by dirt particles or residue of the application media which are deposited in the narrow capillaries, and which can only be inadequately removed, even after intense cleaning efforts, because the bristles in the root area are too close together. These negative effects are exacerbated by the fact that in many brush constructions the bristle carrier is provided with recesses in which the bristle bundles are inserted. In these very small cross-section cavities the bacteria are deposited particularly easily, in the same way as dirt particles and the residues of application media which cannot be removed therefrom.
These disadvantageous effects are noted to a particular extent in toothbrushes, because in this case the aim is to insert bristles with the smallest possible diameters tightly within the bundle, and so that the capillaries and cavities are particularly narrow. Moreover, despite the use of high-grade plastics for the bristles, e.g. polyamides, moisture penetrates the bristle material, and on drying the moisture is not, or is only inadequately, given off. This leads to a change in the strength characteristics of the bristles. The bristles lose stiffness and therefore their recovery capacity, so that their cleaning action no longer corresponds to the original state.
The aforementioned disadvantages occur more particularly in the case of toothbrushes when the dentally recommended cleaning intervals of three times a day is followed, because the intermediate time is insufficient to permit a complete drying of the bristles, particularly in the area close to the carrier.
As a result of these hygienic problems, in the past joining methods from plastic technology were used in fixing the bristles to the bristle carrier, so as to in particular avoid cavities on said carrier in the vicinity of the bristle facing. These in particular include the welding of bristles and bristle carrier (EP 165 546) and the injection moulding of the bristles into the carrier (DE 1 532 809). In conjunction with the welding process (EP 165 546) it has already been proposed not to form the bristle facing from bundles, but also to provide individual, standing or upright bristles in a dense arrangement. The aim is in particular to make the bristle facing such that account is taken of the zonally differing, pronounced wear. This also permits an adaptation of the different areas of the bristle facing to different use functions (cleaning, massage, etc.).
These different use functions are also taken into account in another known construction (GB 2 035 076), in which in the median longitudinal area of the bristle carrier bristle bundles are provided, whereas on either side of said area there are rows of plastic pins having different configurations, the brush head also being curved in the direction of both axes. Therefore the bristles only act on the tooth parts, whereas the relatively soft plastic pins mainly exert a massaging action on the gingiva. Quite apart from the complicated manufacture of such a toothbrush, in the area of the bristle facing is the hygienic problem solved, and the toothbrush does not satisfy modern dental findings for effective cleaning of the teeth and not adequate massaging of the gums in that the brush cannot be guided from the gums to the teeth (red to white).
The aforementioned hygienic problems are supposedly removed in another known construction (EP 60 592), in that the bristle facing comprises, instead of bundles, individual bristles, which are connected to the carrier and also to one another by thermal processes, particularly by laser technology. The bristles are free at their carrier-side end, in that the bristle carrier has a large recess corresponding to the bristle facing contour and the bristles are inserted in said recess in such a way that they are exposed on the back of the carrier. The bristles are only interconnected in the vicinity of said recess and only in the area of their tangent lateral surfaces. This is intended to ensure that through capillaries remain between the bristles, which allegedly make it possible to suck off bacteria and plaque residues. How this takes place and which physical forces are to be used are not disclosed in this document. However, what is decisive is that the bristles must engage on one another at the lateral surfaces, so as to be interconnectable at said surfaces. However, this ultimately means that the same narrow bristle pack exists as in a bundle, because also there the bristles only engage linearly on one another at the lateral surfaces. Thus, the same capillaries form as in the case of a bristle bundle. In addition, it is possible for bacteria to be deposited and grow not just on one side, but on both sides of the bristle carrier.